Page 447 - Analog and Digital Filter Design
P. 447
444 Analog and Digital Filter Design
Chapter 10
10.1 Because surface-mount components have no wire leads, any series
inductance is minimal, and therefore the self-resonant frequency is
high.
10.2 The ferrite core concentrates the magnetic flux to create a high
inductance. The pot-core design ensures that the flux is contained
within the center of the component, which allows designers to place
other inductors adjacent on the circuit board with little likelihood of
altering the inductance or unwanted coupling. Air-gaps are not easily
saturated, thus allowing the inductor to carry DC or high power
levels without affecting the inductance.
10.3 Surface-mount resistors are ideal for radio frequency work because of
their low inductance. Carbon composition resistors are also used
because of their low inductance, although they can be noisy. Wire-
wound resistors have high inductance and are avoided in high-
frequency circuits.
10.4 Using
Fu
Fc=F, FcN'=Fu
Where Fc = 20 kHz and N = 6
FZI = 20 kHz x 36 = 720 kHz.
Op-amps with a gain-bandwidth of 720 kHz or more are easily
available.
Chapter 12
12.1 L > Al20.
M' 8
12.2 -- -
h e.' -&-"
A=- 501111.4 +-fO.46 + E)
3.7
119.9 11.4, 4.7
A = 1.408 + 0.16449 = 1.57249
_- 8 = 1.8167
12'
h - 4.818641 -0.415055
h = 1.6mm, hence w = 1.8167 x 1.6mm = 2.9mm.
